A301964 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.
1, 2, 2, 3, 5, 4, 5, 6, 13, 8, 8, 9, 16, 34, 16, 13, 14, 25, 40, 89, 32, 21, 22, 41, 64, 100, 233, 64, 34, 35, 74, 111, 169, 252, 610, 128, 55, 56, 132, 219, 311, 441, 632, 1597, 256, 89, 90, 239, 443, 749, 874, 1156, 1588, 4181, 512, 144, 145, 437, 904, 1803, 2544, 2454
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..1..0. .0..0..1..0 ..0..1..0..1. .0..0..0..1. .0..1..0..1. .0..0..1..0. .1..1..1..0 ..0..0..0..1. .0..1..0..1. .0..1..0..1. .1..0..1..1. .1..0..1..0 ..0..1..1..1. .0..1..1..1. .1..0..1..0. .1..0..0..1. .0..1..0..1 ..0..1..0..1. .0..1..0..1. .1..0..1..1. .1..1..0..1. .0..1..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..880
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 3*a(n-1) -a(n-2)
k=3: a(n) = a(n-1) +3*a(n-2) +2*a(n-3)
k=4: a(n) = 2*a(n-1) +2*a(n-2) -a(n-3) for n>4
k=5: a(n) = 2*a(n-1) +3*a(n-2) -a(n-3) -2*a(n-4) -3*a(n-5) +2*a(n-6) for n>8
k=6: [order 11] for n>12
k=7: [order 14] for n>17
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-2)
n=2: a(n) = 2*a(n-1) -a(n-3) for n>5
n=3: a(n) = 2*a(n-1) -a(n-4) for n>6
n=4: a(n) = 2*a(n-1) +a(n-3) -a(n-4) -2*a(n-6) +a(n-7) for n>9
n=5: [order 14] for n>17
n=6: [order 27] for n>32
n=7: [order 47] for n>52
Comments